Which circumstance does NOT constitute prior art under patent examination rules?

The circumstance that does not constitute prior art under patent examination rules is when an idea is simply remembered by an inventor. This is because prior art must be documented or otherwise made public in some form that can be accessed and verified by others.

For an invention to be classified as prior art, it must be tangible and accessible, such as through publications, patents, public use, or sales. Merely having a memory of an idea does not meet these criteria, as it lacks the necessary public disclosure or physical manifestation. In contrast, prior sales or offers for sale, an abandoned claimed invention, and documents that have been published all represent formal actions or records that can potentially impact the novelty and non-obviousness of a claimed invention. This is why the remembered idea does not qualify as prior art.